基于分形技术的多分辨率三维地景建模方法研究

介绍了多分辨率分形地景生成方法，以及地景的不同区域具有不同细节层次特点的研究成果。其基本思想是以视点在水平面的投影为参考起来，来生成一个很小的原始数据集，进一步构成多分辨率三角形网络，用以确定地形基座的形状，并用分形技术中的中点位移法及三角形边线细分方案对地形进行递归细分，从而生成自然的地形景观，其多分分辨率基座的构造方法在不需要额外开销的情况下，解决了不同细节层次区域间的空间连续性和时间连续性的

Research of Modeling Method to 3D Multiresolution Terrain Based on Fractal

The real-time terrain generation techniques based on Digital Terrain Model(DTM) have a high requirement to hardware. And in many practical ap plications there is no need to simulate the terrain of certain area. Also people want to generate various terrain with different shape characters in order to me et different requirements flexibly. At this time it is obviously uneconomical to still use the method based on DTM. For this reason, the paper studies the model ing approach to 3D fractal terrain using data as little as possible for the PC. The terrain belongs to the multiresolution model that has several levels of deta il coexisting. The projection of viewpoint is regarded as reference point from w hich a small primitive data set is generated, and forms multiresolution triangle meshes which define the shape of terrain base. Then, iteration is done by midpo int displacement and triangle edge sub-division method. It can produce natural terrains with different shapes. The construction method of multiresolution base has solved “spatial continuity” and “temporal continuity” between areas with different level of detail and avoids holes and seams, at the same time it dose not need extra computing works. Additionally, the base has a expansibility and c an be expanded to needed shapes. The experimental results show that the method i s simple, rapid and suitable for real-time display.